The variable avoid_reserve is meaningless because we never changed its
value and just passed it to alloc_huge_page(). So remove it to make code
more clear that in hugetlbfs_fallocate, we never avoid reserve when alloc
hugepage yet. Also add a comment offered by Mike Kravetz to explain this.
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
fs/hugetlbfs/inode.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 4bbfd78a7ccb..14df2f73b8ef 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -680,7 +680,6 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
*/
struct page *page;
unsigned long addr;
- int avoid_reserve = 0;
cond_resched();
@@ -716,8 +715,15 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
continue;
}
- /* Allocate page and add to page cache */
- page = alloc_huge_page(&pseudo_vma, addr, avoid_reserve);
+ /*
+ * Allocate page without setting the avoid_reserve argument.
+ * There certainly are no reserves associated with the
+ * pseudo_vma. However, there could be shared mappings with
+ * reserves for the file at the inode level. If we fallocate
+ * pages in these areas, we need to consume the reserves
+ * to keep reservation accounting consistent.
+ */
+ page = alloc_huge_page(&pseudo_vma, addr, 0);
hugetlb_drop_vma_policy(&pseudo_vma);
if (IS_ERR(page)) {
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
--
2.19.1
